1. Field of the Invention
The invention relates to surgical instruments and methods. More particularly, the invention relates to methods and apparatus for the minimally invasive treatment of gastric ulcers using a cautery device, although it is not limited thereto.
2. State of the Art
Minimally invasive (also known as endoscopic) surgery is not a new technology. However, it is only in recent years that such surgery has become so widely accepted that it is used in many diverse procedures. Minimally invasive surgery typically involves the making of a small incision (5-10 mm) in the vicinity of the surgical site, the installation of a port through the incision, and the extension of an endoscope through the port to the surgical site. Alternatively, an endoscope is sometimes lubricated and inserted through a body cavity such as the rectum or esophagus.
Gastrointestinal bleeding is a somewhat common and serious condition that can be fatal if left untreated. This problem has prompted the development of a number of endoscopic therapeutic approaches to achieve hemostasis, such as the injection of sclerosing agents, the attachment of mechanical hemostatic devices and contact electrocautery techniques. Mechanical hemostatic devices are typically in the form of clamps, clips, staples, sutures, etc. which are able to apply sufficient constrictive forces to blood vessels so as to limit or interrupt blood flow. Such devices are disclosed in U.S. Pat. No. 6,001,110. Electrocautery techniques involve the use of either monopolar or bipolar electrodes which are contacted to ulcerous tissue. A well known electrocautery device is disclosed in U.S. Pat. No. 5,336,222.
The known clip techniques and cautery techniques are only adequate for relatively small ulcers because the clips and/or cautery probes must be delivered through the working lumen of an endoscope. In addition to optical elements which carry fiber optics to illuminate the surgical site and which deliver an image from the surgical site, the endoscope typically has two or three lumena: one or two lumen(a) for aspiration and irrigation, and one (the working lumen) through which a surgical tool may be passed. The working lumen is typically very small in size (e.g., about 3 mm in diameter), and thus the size of the tools which may be used with a typical endoscope are severely limited in size.
Bleeding gastric ulcer lesions are not limited in size and are frequently too large to be effectively treated with the known mechanical and electrical techniques.
It is therefore an object of the invention to provide methods and apparatus for the minimally invasive treatment of gastric ulcers.
It is also an object of the invention to provide methods and apparatus for the minimally invasive treatment of gastric ulcers using a cautery device.
It is another object of the invention to provide methods and apparatus for the minimally invasive treatment of gastric ulcers using a cautery device which is capable of treating relatively large lesions.
It is a further object of the invention to provide methods and apparatus for the minimally invasive treatment of gastric ulcers using a cautery device which is usable in conjunction with existing endoscopes.
In accord with these objects which will be discussed in detail below, the apparatus of the present invention includes a flexible coil having a proximal end and a distal end (as used herein proximal end means the end closest to the practitioner and distal end means the end closest to the surgical site) with a pull wire extending therethrough. An actuation device is coupled to the proximal ends of the coil and the pull wire for reciprocally moving one of the pull wire and the coil relative to the other. A pair of jaws are coupled to the distal ends of the coil and pull wire such that relative movement of the coil and pull wire causes opening and closing of the jaws. The jaws are rotatably coupled to a clevis means which is adapted to be coupled to the distal end of an endoscope. According to the invention, at least one jaw has an xe2x80x9copenxe2x80x9d structure, with a rim but substantially no jaw cup. The jaws are U-shaped, semi-circular, or horse shoe shaped and are provided with a cautery capability by selectively coupling the coil, the pull wire, or both to a source of cauterizing energy.
According to one of the methods of the invention, the clevis is attached to the distal end of an endoscope and the distal end of the endoscope is delivered to the surgical site with the aid of the optics of the endoscope and with the jaws of the invention closed by activation of the actuation device. A grasper (used herein to denote any instrument such as a forceps, biopsy forceps, snare, suction device or other instrument for mechanically or otherwise grabbing, gripping, or retaining tissue) is inserted through the working lumen of the endoscope. The jaws of the apparatus of the invention are then opened so that the grasper is extended between the opened jaws (typically through the open structure of at least one jaw) to grasp the ulcerous tissue. The grasping instrument is withdrawn to pull the ulcerous tissue between the opened jaws. When the tissue is in place, the jaws of the present invention are closed and the cauterizing energy is activated to cauterize the ulcerous tissue and thereby hemostasis. The procedure may be repeated for treatment of other ulcerous tissue in the vicinity before the apparatus is withdrawn with the endoscope.
According to the presently preferred embodiment, one of the jaws of the cautery device is coupled to the coil and the other is coupled to the pull wire, whereas both jaws are coupled to the clevis. This arrangement permits the jaws to assume two different closed positions: a first closed position wherein both jaws extend substantially parallel and adjacent to the face of the distal end of the endoscope and a second closed position where both jaws extend substantially perpendicular to the face of the distal end of the endoscope. The first closed position is preferred when moving the endoscope to and from the surgical site, and because the jaws have an open structure, the jaws do not block the optical xe2x80x9cvisionxe2x80x9d of the endoscope.
According to a further preferred aspect of the invention, the clevis is provided with upper and lower stops and the coil and pull wire are coupled to the jaws in such a way that different moment arms result. This permits the jaws to be moved from the first closed position to an open position, to the second closed position, and back to the first closed position with a single actuation device having a single linear movement.
According to still another preferred aspect of the invention, the jaws are insulated from each other at their pivotal connection to the clevis so that they may be provided with bipolar cautery capability via separate connections to the coil and pull wire which are also insulated from each other.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.